Hareuveny R, Eliyahu I, Luria R, Meiran N, Margaliot M. Cognitive effects of cellular phones: A possible role of non-radiofrequency radiation factors. Bioelectromagnetics. Apr 12, 2011. Ahead of print.
Introduction
Some studies have shown alterations in cognitive functions during exposure to radiofrequency radiation (RFR) from mobile phones. In their previous studies, the authors found that experiment duration, exposure side and responding hand could influence the detection of cognitive effects. They argued that some confounding factors, such as low frequency magnetic fields from the battery electric current and non-RFR heating from the phone, could mediate the reported cognitive effects.

Objective
The objective of this study was to determine whether the observed cognitive effects could be attributed to RFR or to other factors.

Methods
Participants were 29 healthy right-handed men. Each participant had two Nokia 5110 GSM cellular phones attached to both sides of his head. The experimental system was identical to that used in the authors’ previous experiments except for one innovation: external antennas placed about 2 m away from the subjects were connected to the cellular phones preventing emission of RFR from the cellular internal antenna. This design drastically reduced RFR exposure but did not change non-RFR factors (non-RFR heating and low-frequency magnetic fields). The subjects were randomly divided into two groups exposed to only one exposure condition: left side of the head (n=15) or right side (n=14). There was no sham-exposed group. The experimenter was aware of the exposure condition but the subjects were not. The subjects performed the same spatial working memory task as in the authors’ previous experiments.

Results and Interpretation
Similar to the previous experiments, the average response time (RT) of the right-hand responses under the left side exposure was longer than the average RT under the right-side exposure. These findings indicate that the effects previously attributed to RFR could result from non-RFR factors, possibly from non-RFR heating and low-frequency magnetic fields.

Conclusion
The authors have concluded: “Only by ruling out non-RFR agents as a source of an effect can one argue that RFR can indeed influence the central nervous system or cause any other effect”.